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Subject: Re: Is Lokasoft's claim correct?

Author: Uri Blass

Date: 04:52:41 02/25/04

Go up one level in this thread


On February 25, 2004 at 07:35:53, Sune Fischer wrote:

>
>>>
>>>I believe that this is not really a tactical shoot, this is an evaluation based
>>>sacrifice. Some engines will find this very fast, others won't find it at all.
>>
>>I agree
>>I saw no claim that it is a tactical sacrifice.
>>
>>My program see +0.16 for black at depth 13 after Nxc3 bxc3
>>It probably can find Nxc3 from the root position after enough time but it was
>>not important enough for me to check.
>>
>>After Nxc3+ bxc3 the score is positive since depth 10.
>
>If I'm not mistaken white gets two minors for a rook and pawn + a busted pawn
>shelter.
>
>The two knights for the rook and pawn is evaluated as good white in frenzee,

2 knights for rook and pawn is evaluated as good for white in most programs.

>and I don't give huge scores for a busted shelter when there is no eminent
>attack.
>
>I haven't analyzed the position thoroughly but to me it looks like the black
>pieces aren't coordinated very well for an attack(?), and white has some
>defensive capabilities as well.
>
>I question if it is not too speculative to sacrifice here without a deeper
>search to see if the attack is really dangerous or not.
>
>Ruffian's tuning seems more balanced, as posted elsewhere on this thread it
>doesn't jump at it instantly but takes a little while before it convinces itself
>that the sac is 'good enough'.

Movei also does not jump at it instantly.

>
>Frenzee fails high by about 0.4 pawn for white after the exchange and it stays
>that way for a few minutes. I guess if I give 0.5 pawn more for a busted shelter
>it too will find the amazing sacrifice instantly :)
>
>>>
>>>Mine still likes white better after Nxc3 bxc3 and a few minutes of search.

I suspect that it did not search deep enough

Here is yace analysis after 1...Nxc3 2.bxc3 Nd5 3.Rc1 cxd4

New game
[D]2rq1rk1/pb1p2pp/1p2p3/3n1p2/3p2P1/P1PBPN1P/3NQP1R/1KR5 w - - 0 1

Analysis by Yace Paderborn:

4.exd4 Nxc3+ 5.Rxc3 Rxc3
  µ  (-0.94)   Depth: 1   00:00:00
4.cxd4
  +-  (1.83)   Depth: 1   00:00:00
4.cxd4
  +-  (1.83)   Depth: 1   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3
  +-  (1.42)   Depth: 2   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.gxf5 Bxf3 7.Nxf3 Rxa3 8.fxe6 Rxd3 9.Qxd3 Rxf3
  ²  (0.42)   Depth: 2   00:00:00
4.cxd4 Nc3+ 5.Rxc3
  =  (0.10)   Depth: 2   00:00:00
4.cxd4 Nc3+ 5.Rxc3
  =  (0.10)   Depth: 2   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3
  =  (0.10)   Depth: 3   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3
  =  (0.10)   Depth: 3   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2
  =  (-0.22)   Depth: 4   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2
  =  (-0.22)   Depth: 4   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5
  ³  (-0.26)   Depth: 5   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5
  ³  (-0.26)   Depth: 5   00:00:00
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5 exf5
  ³  (-0.26)   Depth: 6/20   00:00:00  118kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5 exf5
  ³  (-0.26)   Depth: 6/21   00:00:01  307kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5 Bxf3 8.Nxf3
  =  (0.02)   Depth: 7/21   00:00:01  420kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.gxf5 Bxf3 8.Nxf3
  =  (0.02)   Depth: 7/24   00:00:03  646kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.Ne5 f4 8.Nxd7 Rc8
  =  (-0.14)   Depth: 8/24   00:00:04  1008kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.Ne5 f4 8.Nxd7 Rc8
  =  (-0.14)   Depth: 8/27   00:00:10  2560kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.Ne5 f4 8.Nxd7 Rc8 9.Nc5
  =  (0.09)   Depth: 9/27   00:00:14  3963kN
4.cxd4 Nc3+ 5.Rxc3 Rxc3 6.Kb2 Qc7 7.Ne5 f4 8.Nxd7 Rc8 9.Nc5
  =  (0.09)   Depth: 9/28   00:00:22  5856kN
4.cxd4 Rxc1+ 5.Kxc1 Qc8+ 6.Bc2 Ba6 7.Qd1 fxg4 8.Ne5 g3 9.Qh5 Bd3 10.Kd1 gxh2
11.Bxd3
  =  (0.09)   Depth: 10/31   00:00:39  11155kN
4.cxd4 Rxc1+ 5.Kxc1 Qc8+ 6.Bc2 Ba6 7.Qd1 fxg4 8.Ne5 g3 9.Qh5 Bd3 10.Kd1 gxh2
11.Bxd3
  =  (0.09)   Depth: 10/31   00:01:00  16648kN
4.cxd4 Rxc1+ 5.Kxc1 Qc7+ 6.Bc2 Nc3 7.Qf1 Rc8 8.Kb2 Ne4 9.Bb3 Nxd2 10.Ka2
  ³  (-0.31)   Depth: 11/34   00:01:15  21007kN
4.cxd4 Rxc1+ 5.Kxc1 Qc7+ 6.Bc2 Nc3 7.Qc4 Qxc4 8.Nxc4 Bxf3 9.Ne5 Bc6 10.Nxc6 dxc6
11.g5
  ³  (-0.62)   Depth: 11/34   00:01:36  26788kN

(Blass, Tel-Aviv 25.02.2004)


When I go backward it does not find significantly better move for white inspite
of the fact that 3.Kc2 seems to it slightly better

New game
[D]2rq1rk1/pb1p2pp/1p2p3/2pn1p2/3P2P1/P1PBPN1P/3NQP1R/1K1R4 w - - 0 1

Analysis by Yace Paderborn:

3.dxc5 Nxc3+ 4.Ka1 Nxe2 5.Bxe2 Rxc5
  -+  (-5.35)   Depth: 1   00:00:00
3.gxf5 Nxc3+ 4.Ka1 Nxe2 5.Bxe2 Rxf5
  -+  (-5.25)   Depth: 1   00:00:00
3.Ba6 Nxc3+ 4.Ka1 Nxe2 5.Bxb7
  -+  (-5.01)   Depth: 1   00:00:00
3.Qe1 Nxc3+ 4.Kc1 Nxd1 5.Kxd1 cxd4 6.Nxd4 fxg4
  µ  (-1.00)   Depth: 1   00:00:00
3.Qf1 Nxc3+ 4.Kc1 Nxd1 5.Kxd1 cxd4 6.Nxd4 fxg4
  µ  (-0.99)   Depth: 1   00:00:00
3.c4
  +-  (2.09)   Depth: 1   00:00:00
3.c4
  +-  (2.09)   Depth: 1   00:00:00
3.c4 Nc3+ 4.Ka1 Nxe2
  -+  (-3.22)   Depth: 2   00:00:00
3.c4 Nc3+ 4.Ka1 Nxe2 5.Bxe2
  -+  (-4.26)   Depth: 2   00:00:00
3.c4 Nc3+ 4.Ka1 Nxe2 5.Bxe2 Bxf3 6.Nxf3 cxd4 7.Nxd4 fxg4
  -+  (-4.91)   Depth: 2   00:00:00
3.Qf1 Nxc3+ 4.Kc1 Nxd1 5.Kxd1 cxd4 6.Nxd4 fxg4
  µ  (-0.99)   Depth: 2   00:00:00
3.Qf1 Nxc3+ 4.Kc1 Nxd1 5.Kxd1 cxd4 6.Nxd4 fxg4
  µ  (-0.99)   Depth: 2   00:00:00
3.Rc1 cxd4 4.cxd4 Rxc1+ 5.Kxc1 Qc7+ 6.Bc2 Nc3 7.Qc4 Qxc4 8.Nxc4 Bxf3 9.gxf5 Rc8
10.Ne5 Be4 11.f3
  ³  (-0.62)   Depth: 2   00:00:00
3.Rc1 cxd4 4.cxd4 Rxc1+ 5.Kxc1 Qc7+ 6.Bc2 Nc3 7.Qc4 Qxc4 8.Nxc4 Bxf3 9.gxf5 Rc8
10.Ne5 Be4 11.f3
  ³  (-0.62)   Depth: 2   00:00:00
3.Kc1 cxd4
  =  (-0.10)   Depth: 2   00:00:00
3.Kc1 Nxc3
  ±  (0.96)   Depth: 2   00:00:00
3.Kb2 cxd4
  ±  (1.14)   Depth: 2/12   00:00:00
3.Kb2 cxd4 4.cxd4
  +-  (1.43)   Depth: 2/12   00:00:00
3.Kb2 cxd4 4.cxd4
  +-  (1.43)   Depth: 2/12   00:00:00
3.Kb2 cxd4 4.cxd4
  +-  (1.43)   Depth: 3/12   00:00:00
3.Kb2 cxd4 4.cxd4
  +-  (1.43)   Depth: 3/12   00:00:00
3.Kb2 cxd4 4.Nf1 dxe3 5.fxe3
  ±  (1.03)   Depth: 4/12   00:00:00
3.Kb2 cxd4 4.c4 Nc3
  ²  (0.66)   Depth: 4/12   00:00:00
3.Kb2 cxd4 4.c4 Nc3
  ²  (0.66)   Depth: 4/12   00:00:00
3.Kb2 cxd4 4.Bxf5 exf5 5.c4
  ²  (0.26)   Depth: 5/12   00:00:00
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1
  =  (-0.11)   Depth: 5/12   00:00:00
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1
  =  (-0.11)   Depth: 5/12   00:00:00
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Bd5 7.gxf5 exf5
  =  (-0.21)   Depth: 6/15   00:00:01  70kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Bd5 7.gxf5 exf5
  =  (-0.21)   Depth: 6/23   00:00:01  116kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Qc7 7.gxf5 exf5
  =  (-0.16)   Depth: 7/23   00:00:01  186kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Qc7 7.gxf5 exf5
  =  (-0.16)   Depth: 7/23   00:00:01  288kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Qc7 7.Qc2 Qxc2+ 8.Bxc2 fxg4
  ³  (-0.39)   Depth: 8/23   00:00:02  594kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Qc7 7.Qc2 Qxc2+ 8.Bxc2 fxg4
  ³  (-0.39)   Depth: 8/28   00:00:04  955kN
3.Kb2 cxd4 4.cxd4 Nc3 5.Qf1 Nxd1+ 6.Qxd1 Qc7 7.Qc2 Qxc2+ 8.Bxc2 fxg4 9.Ne5 gxh3
10.Nxd7
  ³  (-0.49)   Depth: 9/28   00:00:07  2002kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 Bxf3+ 7.Nxf3 f4 8.exf4
  ³  (-0.48)   Depth: 9/31   00:00:13  3642kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 Qe7 7.exd4 Qxa3
  ³  (-0.44)   Depth: 9/31   00:00:14  4053kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 Qe7 7.exd4 Qxa3
  ³  (-0.44)   Depth: 9/31   00:00:14  4053kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 dxe3 7.Qxe3 Qf6 8.gxf5 Qa1+ 9.Ke2 exf5
  ³  (-0.43)   Depth: 10/34   00:00:40  12875kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 dxe3 7.Qxe3 Qf6 8.gxf5 Qa1+ 9.Ke2 exf5
  ³  (-0.43)   Depth: 10/34   00:00:51  15732kN
3.Kc2 cxd4 4.c4 Nc3 5.Qe1 Nxd1 6.Kxd1 dxe3 7.Qxe3 Qf6 8.gxf5 Qa1+ 9.Ke2 exf5
  ³  (-0.43)   Depth: 11/40   00:02:03  40107kN

(Blass, Tel-Aviv 25.02.2004)

Uri



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